Snubbed spring group



N 1954 L F. RAMOS ETAL SNUBBED SPRING GROUP Filed Feb. 7, 1951 (277206 ezunann INVENTORS.

Z P 2V in??? I SNUBBED SPRING GROUP Lawrence F. Ramns and'fitto W. Neurnann,Chi c,ago,;Ill., assignors to American Steel Foundries, Chicago, Ill., a corporation of New Jersey Application February 7, 1951, Serial No. 209,809

12 Claims. (Cl. 267 9) This invention relates to friction snubbing devices and moreparticularly to a novel package sprin-g group incorporating such a device and adapted for suspension of afreight car truck bolster.

Aprimary object of'the invention isto devise a friction device such-as above described which is adapted -to accommodate relative rocking movement between the bolster and its supporting frame which carries the friction device and spring group.

A further object of the invention is to accommodate automatic adjustment of the friction shoes to compensate for wear which normally takes place between the shoes and friction surfaces of such devices.

A further object of the invention is to devise a novel package spring group wherein relative rocking movements of the bolster and frame are resiliently .resisted without substantial development of friction, and vertical movementis of the bolster are resiliently and frictionally resiste The foregoing and other objects and advantages of the invention will become apparent from "a considerationof thefollowing specification and the accompanying drawings, wherein:

Figure l is a transverse vertical sectional view'of a package spring group embodying the invention, the section being taken in a vertical plane approximately bisecting the group on its transverse axis about which-the group is symmetrical;

Figure 2 is a fragmentary end view of the group shown in Figure l, partly in section along theplane indicated by'the line 22 thereof; I

Figure 3 is a'sectional view "on line 33 of "Figure 2.

Describing the invention in detail, the novel package spring group comprises "a top plate or follower generally designated 2 and having a'depending flange 4 about its perimeter to confine the'upper ends of a plurality of conventional truck springs 6, adapted to support the load of an associated truck 'bolster (not shown) which normally seats on the 'top plate or follower 2 and is positioned by lugs'or bosses'8 thereof.

The lower ends of the springs 6 are supported by a bottom plate or follower 10 adapted to seat on thegframe (not shown) of a freight car truck and to be positioned relative thereto by depending lugs or bosses 12. The plate or bottom follower 10 is preferably in the form of a casting having lateral flanges 14 at the sides thereof adapted to confine the lower ends of the springs 6 and integrally formed with upstanding panels or walls 16 to which wear plates 18 are preferably secured in any con venient manner, as for example, by welding at 20.

The bottom follower 10 also comprises side walls 19 having slots or recesses 21 in their upper edges, for a purpose hereinafter described. As best seen in Figure 2, the bottom plate or follower 10 is also provided with end flanges 22 confining the springs 6 and each being refianged as at 24 to define a substantially horizontal projection or lug with an opening 26 receiving a bolt and nut assembly 28 which projects through a similar opening 30 in a lug or projection 32 formed as a reflanged portion of the top follower flange 4. The upper end of the bolt and nut assembly 28 is preferably secured as by welding at 34 to the lug 32 and is reciprocal within the opening 26, as the novel package group is alternately compressed and released under operating conditions. As shown at the left of Figure 2, a removable plate or bar 36 bears against the underside of the lug 24 and against United States Patent 2,695,167 Patented Nov. 23, 1954 2. an annular-stop plate or washer 38, secured as by welding at 40 to the bolt and nut assembly 28. 'Thus the plate 36 and the corresponding plate at the opposite-end (not shown) of the novel springgroup function to=-ma-intain it under pre-compression during assembly of the device in an associated freightcar truck. aUpon removal of the plate 36, the springs 6 urge the stop Washer 318 against the underside of the lug 'or web 2410 limit=expansion of the package group.

The novel friction device of the packagevgroup comprises a pair of friction shoes 42, generally triangular in shape, as seen in the sectional view of :Figure 1, "and each having a pair of arms .or lugs i l-formed with hubs 46 rockably engageable as at 48 with the top :plate '01 follower 2, upon compression of the spring group. The

hubs 46 are received within a slot 50 .definedby a depending U-shaped bar or web 52xformed on the underside 'of a top plate 2. The bar 52 is provided with an arcuately upwardly facing surface 54 engageable with complementary surfaces of the hubs 46 upon expansion .of'thespring group. Thus an articulated or jointed connection 'lSIiPlO- vided between the friction shoes 42 .and the top follower 2. The bar 52 is adapted for reception within the slots 21 of the walls 19 upon compression of the group. Thus,.as will be readily seen in Figure 1., transverse rocking .of the upper follower 2 relative to the lower follower 1.0 :is accommodated at all times.

The frictionshoes 42 are provided, respectively, with wedge faces 55 converging upwardly, as seen in Figure 1, toward the bar 52 and engageable with complementary surfaces of a hollow wedge 56 containing the upper .end

of 5agcompression coil'spring diagrammatically indicated at The lower end of the spring 58 :is seated against the bottom follower 10, and the upper end of the spring 58 is seated as at 60 against a spring seat of :the wedge lying in a substantially horizontal plane intersecting the shoe surfaces 55, as well as the .surfaces of the wear plates 18 against which the shoes 42 are urged by the wedge 56 under the action of its spring 5:8.

As best seen in Figure 3, the arms 44 .of reach shoe are alternately arranged'or interlaced with'the arms 1440f the other shoe to position the shoes against relative-dis:

placement longitudinally of'the spring group andtogaiford a compact arrangement wherein maximum bearinglareas are afforded at 48 and 55 for the hubs .46 of "the/shoes upon compression and release, respectively, =ofthe novel package group.

. Referring to Figure 1, it will'beseenthatthe top plate or follower 2 may rock at any "given time during compression and release of the spring group .on fan axis approximately parallel to the friction faces :of the wear plates 18 against which the shoes '42zare engaged. Flhus assuming that the package group isin normal {expanded position, this rocking action may take place without urgr ing the shoes 42 upwardly or downwardly against the plates 18 so that the rocking action is yieldingl-y resisted, by springs 6, without substantial development of friction. This arrangement affords a-soft'cu'shionin'g resistance to such rocking movements when the package group is in normal released position. However, it will also be seen in Figure 1, that such rocking movements of the top follower 2, accompanied by vertical movements thereof, is effective to develop friction between the shoes 42 and the wear plates 18, and extreme rocking movements of the top follower 2 may cause engagement thereof with the upwardly facing surfaces of the arms 44 of one shoe, thereby urging it downwardly relative to the other shoe to increase frictional resistance to such excessive rocking action.

It may be noted that the preferred embodiment illustrated shows only one pair of shoes 42 and one shoe actuating spring 58, however, it will be understood that, if desired, these parts may be multiplied.

We claim:

1. In a friction device of the class described, a pair of followers, one of said followers having spaced friction surfaces, friction shoes having articulated connections to the other follower on a common axis approximately parallel to said surfaces and extending horizontally intermediate said surfaces, wedge means engageable with and interposed between said shoes for urging them against respective surfaces, and spring means compressed between the wedge means and said one follower for actuating said wedge means.

2. In a friction device of the class described, a follower having spaced friction surfaces, friction shoes engaged with respective surfaces, another follower hinged to said shoes, a resilient unit carried by one follower and operatively engaged with the shoes for urging them against said surfaces, and converging abutments on each shoe and said other follower engageable during extreme rocking movement of the latter to urge said shoe along the related surface.

3. In a friction device of the class described, a follower having spaced opposed friction surfaces, friction shoes engageable therewith, and means for resiliently urging said shoes against said surfaces, and another follower rockably seated against upwardly facing converging surfaces on said shoes, said other follower having means underlying said upwardly facing surfaces and rockably engageable with downwardly facing surfaces of said shoes upon expansion of the device, said means accommodating pivotal movement of the shoes relative to the other follower on an axis extending parallel to said friction surfaces.

4. In a friction device of the class described, a follower having spaced friction surfaces, friction shoes engageable with said surfaces and having interlaced arms formed at their extremities with hubs, another follower having a slot receiving said hubs and snugly confining the same to rockably interlock the other follower with said hubs, and means carried by the first-mentioned follower for yieldingly engaging the shoes with said surfaces.

5. In a friction device of the class described, a follower having spaced friction surfaces, friction shoes engageable with respective surfaces, another follower having opposed facing abutment surfaces, said shoes having arcuate hubs extending between the last-mentioned surfaces and engageable therewith along a single plane extending between the friction surfaces and approximately parallel thereto, and means for urging the shoes against the friction surfaces.

6. In a package spring group, spaced spring plates, a plurality of springs compressed therebetween, members on one of said plates carrying opposed friction surfaces, friction shoes engageable with respective surfaces, 21 bar carried by the other plate on the inner side thereof and defining a slot therewith, curved hubs on said shoes projecting into said slot for rockable engagement with said bar and other plate on the expansion and compression strokes, respectively, of the group, a wedge engaged with said shoes along surfaces converging toward the bar, and spring means compressed between said wedge and said one plate for urging the wedge into engagement with the shoes and thereby urging the shoes against the related friction surfaces.

7. In a package spring group, spaced spring plates, a plurality of compression springs interposed therebetween, members having spaced friction surfaces on one of the plates, spaced friction shoes hinged to the other plate, wedge means between said shoes in wedge engagement therewith, and a compression spring between said wedge means and said other plate.

8. In a package spring group, spaced spring plates, a plurality of compression springs interposed therebetween, and a friction device in parallel with said springs, said device comprising members having friction surfaces on one of the plates, friction shoes engageable with said surfaces, wedge means for urging the shoes into engagement with said surfaces, a compression spring between said wedge means and said plate, and means hinging the shoes to the other plate for rocking movement relative thereto on an axis defined by a plane bisecting the last-mentioned spring and passing between said surfaces without intersecting them.

9. In a friction device of the class described, a pair of followers, friction shoes in frictional engagement with one of the followers, a compression spring carried by said follower, wedge means operatively connectedto the spring and engaged with the shoes for actuation thereof, and interlaced arms on said shoes hinged to the other follower.

10. A friction device of the class described, comprising spaced followers, friction shoes having interlaced arms rockably hinged to one of the followers, and a resilient unit in pressured engagement with the shoes and the other follower for urging the shoes into frictional engagement with said other follower.

11. A friction device of the class described comprising a pair of followers, friction shoes hinged on a fixed axis to one of the followers, and means carried by the other follower for urging the shoes into frictional engagement therewith, said means comprising a compression spring having a compressional axis passing through the hinge axis of the shoes.

12. In a friction device of the class described, spaced parallel resiliently interconnected followers, at least one friction surface on one of said followers, at least one friction shoe cooperating with said surface and having an articulated connection to the other of said followers, said connection accommodating pivotal movement of said shoe on an axis parallel to the followers and the surfaces, resilient means engaging said one follower and urging said shoe into pressured contact with said surface, said resilient means comprising a wedge, and means to guide the wedge into engagement with said shoe.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 207,020 Dick et a1. Aug. 13, 1878 1,073,102 Dorey Sept. 16, 1913 1,442,893 Lewis Ian. 23, 1923 1,882,801 Geiger Oct. 18, 1932 2,152,388 Porter Mar. 28, 1939 2,365,199 Light Dec. 19, 1944 2,366,181 Cottrell Jan. 2, 1945 2,396,796 Lounsbury Mar. 19, 1946 2,481,030 Link Sept. 6, 1949 FOREIGN PATENTS Number Country Date 50,372 France Ian. 16, 1940 

